This application claims priority over provisional application Ser. No. 60/405,826 filed Aug. 26, 2002.
The apparatus described and claimed herein relates generally to electronic-optical packages, and more particularly to grids or arrays of such packages supported in such manner as to facilitate their installation and use as in closely assembled or packed configurations. Provisional application Ser. No. 60/405,826 is incorporated herein by reference.
Large-scale LED displays are typified by the use of T 1 3/4  (5 mm) packaged LEDs soldered to rigid printed circuit boards. Such circuit board/modules typically contain a large number of LEDs and must be replaced to correct for the failure of even a single LED. In addition to cost, weight and volume issues or problems, these displays are limited in resolution as a result of the LED package size (typically 0.2 inches in diameter), or about 300 times the plan form area of a bare LED (8000 times the volume), and they are limited in brightness by the small number of LEDs that can be placed in a given area, and also by the thermal resistance of the package and module design. The resolution limit is a function of spacing that is further restricted by package (LED) size. The brightness limit is a function of the number of LEDs per unit area and their individual light output, which is further dependent on the thermal resistance between the LED junction and the local environment. Also, existing LED signage and displays have limited ability to tailor the radiation emission pattern to the needs of the target/audience and thereby increase efficiency. Increased efficiency allows for reduced system and operating cost and/or more radiation delivered to the target.
There is need for improvements in LED display assemblies that overcome problems of heating and inability to adequately transfer or dispose of heat generated by LED operation; problems of inadequate LED support on substrates or circuit boards; problems resulting from lack of flexibility of the LED support means; difficulties in manufacturing close packed LED displays; and other problems and difficulties as will appear.